1. Field of the Invention
The present invention relates to missile separation devices and more particularly to the device which separate a propulsion system from a missile.
2. Description of the Background Art
A missile is manufactured to be separated into plural stages for an efficient flying toward a designated point. A variety of separating devices for separating the stages of the missile have been developed. In particular, a missile system with a launcher requires a separation of a coupling system for connecting the missile when the missile is ejected in its launching direction.
Commonly-used typical separation mechanisms include a mechanism in which two stages of a missile are coupled by bolts and explosives mounted in the bolts are exploded at a preset time, thus to break the bolts for separation (U.S. Pat. Nos. 4,648,321 or 5,400,713), a band cutter adapting explosive bolts (U.S. Pat. No. 4,719,858), and the like. Such self-explosive pyrotechnic devices have been well known as opportunely performing the stage-separation of the missile at a process of launching a missile.
However, a considerable impact may occur upon the cutting operation and accordingly a great impact loading may be applied to components near the pyrotechnic device, thereby standing a chance of causing vital problems in precision components or optical systems. As one example, an electromagnetic interference (EMI) shielding is required for preventing the detonation of a weapon due to electromagnetic waves generated at the time of explosion. Also, even if the pyrotechnic device is very reliable, it is difficult to perform an electric test to a system of the pyrotechnic device once being installed, due to the dangerousness of electric or electromagnetic signals by which the pyrotechnic device can be detonated.
Next, in order to receive power required for the detonation of the pyrotechnic device, a battery overload may occur or battery capacity should be increased.
Furthermore, a technical solution is required for sufficiently protecting the pyrotechnic devices from an easily corroded environment, e.g., from moisture. In order to overcome such drawbacks, various schemes or devices have been proposed, including a method using a gas generator (U.S. Pat. Nos. 4,171,663 or 5,253,587), a parallelogram structure (U.S. Pat. No. 4,291,931), a device using wire or metallic foil as an electric fuse (U.S. Pat. No. 5,046,426), a device using a heating mechanism and complex cable (U.S. Pat. No. 6,439,122), and the like. However, such schemes and devices should be provided with separate equipment and even increase a minimum section area of a missile, resulting in the generation of drag, causing a degradation of performance of a missile or an increase in a fabricating cost. Furthermore, a system using a wire or metallic foil should be configured such that all of the wires and metallic foils are connected to an electric circuit, respectively, which makes the structure complicated, thereby lowering productivity and reliability of the system.